Sergio found 4 pennies on the ground his sister said that she found 2times as many pennies Sergio figured out that his sister found 6 pennies .what did Sergio do wrong

Sergio found 4 pennies on the ground and her sister said that she found twice as many as him

When his sister said that she found twice as many, sergio added 2 to his number of pennies instead of multiplying by 2

That's where Sergio made a mistake and got the answer wrong